Inner containers of the afore-mentioned kind are used as an exchangeable component of transport and storage containers, which serve to transport and store liquids and are commonly used as so-called circulating containers, which are filled repeatedly. To achieve a maximum turnover volume of the liquids filled into inner containers, it is substantial to ensure that the container is emptied as completely as possible so that the entire container volume is available for refilling in the next filling process. Furthermore, it is also important to achieve an emptying as complete as possible of the container in the interest of an economic, substantially complete utilization of the content of the container and to avoid costly purging and cleaning processes.
A substantially complete draining of the known inner containers may prove very elaborate and time-consuming in particular in connection with highly viscous filling products which exhibit good wetting properties with regard to the inner walls of the inner container because the shape of the container is substantially aimed at providing a container with a maximized container volume which is additionally adapted in terms of its exterior dimensions and its design to the receiving space defined on the transport pallet within the outer mantle.
With respect to emptying the inner container as completely as possible, particular problems arise in the storage of thixotropic liquids such as lacquers whose viscosity must usually be reduced by stirring in order to allow a subsequent removal of the lacquers from the container and subsequent processing of the lacquers by spraying surfaces to be lacquered, for example. After an incomplete emptying of the container, the viscosity of the resting liquid increases again so that the amount of lacquer remaining in the inner container has to be stirred up again before performing another lacquering process.
Stirring up a residual or partial amount which remains in the inner container as a result of a successive removal of partial amounts, for example, is necessary in practice not only with lacquers but basically with all liquids that may exhibit separation due to storage. Separated dispersions, for example, can be homogenized by stirring. A residual amount that cannot be stirred up, such as a separated lacquer, is useless and may have to be disposed of in a costly manner.
For stirring, stirrer devices are usually introduced into the inner container through the filling opening formed in the upper bottom wall of the inner container, by means of which the residual amount remaining in the inner container can be stirred up. To completely use up the lacquer remaining in the inner container, it is necessary that the residual amount can be stirred up as completely as possible, i.e. that the stirrable residual amount is minimized so as to be able to use up the entire content of the container in the economic interest of the lacquer processor.